Carburetor



Oct. 2-9, 1929. w. L. GUY 1,733,122

CARBURETOR Filed Feb. 26, 1926 5 12 .||l"' h 4 2 3 C 5 8 I I luwmne:

MLLIANI G Y Mimi tion immediately opposite the top edge of the Patented Oct. 29, 1929 m ss STATES PAT ENfll OFFICE IA. 0. LIMITED, or BIRMINGHAM,

ENGLAND, A BRITISH COMPANY GARBURETOR Application filed February 26, 1926, Serial No.

This invention relatesto carburetors for use with internal combustion engines, of the kind in which the fuel issupplied by a nozzle situated'in a venturi forming a primary air supply pasage into which is admitted a controllable supply of air, and the mixture thus obtained is delivered into the main air passage of the carburetor, usually at the throat of a choke tube therein, or at a part adjustably restricted by a throttle valve.

A (IQIlStfllCblOIl has previously been proposed in which controllable air was admitted into the primary air passage at a position adj acent the latters entry into the main air passage and entirely remote from the fuel nozzle or restricted part containing it, and it 7 served, therefore, merely to dilute the mixture delivered. The principal object of the present invention, however, isto secure more perfect atomization of the fuel as well as to provide for varying themixture strength.

In another proposed construction, a fuel. nozzle has been located in a concentrically. arranged atomizer tube in the main air pas-- sage of the carburetor, and this tube was provided with apertures at the level of the top of the nozzle, and also at a position near its outlet end, both sets of apertures being controllable by means of a rotatable sleeve surrounding the atomizer tube.

According to this invention, the whole of the controllable air supplied to the primary. air passage is adapted to be admitted later ally into the Venturi tube therein at a posifuel nozzle.

In the preferred method of carrying out the invention, which is illustrated in the accompanying vertical section, the carburetor has a horizontal main passageway 2 controlled by a main throttle valve 3, and the primary air passage 4: is vertically arranged in the lower wall of the main air passage.

Within this primary air passage is located a Venturi choke tube 5, the upper edge of which may, if preferred, project somewhat into the main air passage 2. The choke tube is preferably contained in the thickened por-- tion of the carburetor body into the-under face of which is screwed the fuel nozzle 6 and 90,881, and in Great BritainlMarch 5,1925.

any suitable methodof connecting the latter with a constant level fioatjchamber (not shown) is adopted. v l

A comparatively small annular space is provided between the side'of the fuel nozzle and the wall of the Venturi tube 5, andthis forms a restricted passage for the supply of a certain amount of primary air which enters at 7, and, under normal conditions, re-

I quires no adjustment.- Obviously, however,-

to suit certain engines, and/or certain kinds of fuel, the quantity of air thus'admitted would be determinedinitially byexperiment and the .air passage at the mouth. of the venturi arranged accordingly,

Lateral apertures orpassages are in the sideof the venturi 5, for example, one or more holes such as 8, and the lower edges of these passages (i. e., those-nearest to, the inlet of the venturi) are level or substantially so with the outlet of the fuel nozzle 6. Air

reaches the hole or holes 8 through a passage 9 and annular chamber 10, and the inlet 12 to this passage is controlled by any suitable kind of valve, such, for example, as a springloaded plug valve 11 which normally closes the inlet to it but is adjustable by cable or other mechanism. f l

By the foregoing arrangement, it is possible to control very effectively the mixture strength'merely by adjustment of the air supply to the aperture 8 or apertures in the venturi 5, and there is no necessity whatever to rovide in the main passageway 2, an unduly small choketube, into the throat of-which the pr mary mixture passage would'deliver;

.A specially important feature, however, is

the thorough atomization of the fuel which 1. In a carburetor having a main passageprovided A WILLIAM'L ESLIE GUY, OF BIRMINGHAM, ENGLAND, ASSIGNOR OF ONE-HALF TO A.

. way, a choke tube in communication with and forming the sole opening through the wall of said choke tube between the outlet of the nozzle and the mouth of the choke tube, and means for controlling the admission of air through said aperture.

2. In a carburetor for an internal combustion engine, the combination of a main passageway, a slidable throttle valve controlling said passageway, a choke tube opening into said main passageway so that flow through this passageway takes place across its outlet, a fuel nozzle within said choke tube between which latter and the nozzle is an annular space forming a restricted passage for the supply of primary air, a lateral aperture in the ide of said choke tube having its lower edge substantially level with the outlet of the fuel nozzle, a passage connecting said aperture with the atmosphere, a plug valve adapted normally to close the inlet to said latter passage under the action of a spring,

and means for adjusting said plug valve to regulate the air admitted to said latter passage, substantially as set forth.

,3. In a carburetor for an internal combust1on engine, the combination of a main passageway, a tubular slidable throttle valve controlling said passageway, a choke tube coaxial with said throttle valve projecting into said passageway and having its axis trans verse thereto, a fuel nozzle within said choke tube between which latter and the nozzle is a restricted annular space, a passage adjacent the inlet of said choke for uncontrolled entry into said annular space of a small quantity of primary air, a lateral aperture in the side of said choke tube having its lower edge substantially level with the outlet of the fuel nozzle, a passage connecting said aperture with the atmosphere,'a plug valve adapted normally to close the inlet to said latter passage under the action of a spring, and means for adjusting said plug valve to regulate the air admitted to said latter passage, substantially as set forth.

4. In a carburetor for an internal combustion engine, the combination of a body, a

horizontal main passageway therein, a tubular throttle valve slidable transversely across said passageway, a choke tube coaxial with said throttle valve, a parallel sided throat in said choke tube, a fuel nozzle having parallel sides arranged in said choke and providing between it and the choke tube a relativel long and restricted passage for the supp y ofprimary air, an opening in said carburetor body adjacent the inlet of said choke for uncontrolled entry of primary air into said annular space, a lateral aperture in the side of said choke tube having its lower edge substantially level with the outlet of said fuel nozzle, a horizontal passage connecting said aperture with the base of a verticalbore in the carburetor body, an aperture in the side of said bore connecting the interior of said bore with the atmosphere, a plug valve normally closing said aperture in said bore under spring pressure, and means for positively actuating said plug valve to admit air into said vertical bore and thereby to the interior of said choke tube, substantially as set forth. In testimony whereof I have name to this specification.

WILLIAM LESLIE GUY.

signed my 

